DTC Troubleshooting: P0088 (K20C1) - Honda Civic FC/FK 2016-2021

DTC Troubleshooting: P0088

DTC P0088: Fuel Rail Pressure Too High

NOTE:

	Before you troubleshoot, review the general troubleshooting information.
	If any of the DTCs listed below are stored at the same time as P0088, troubleshoot those DTCs first, then recheck for P0088. P0190, P0191, P0192, P0193: Fuel rail pressure sensor P0201, P0202, P0203, P0204: No. 1?No. 4 cylinder injector(s) P0351, P0352, P0353, P0354: No. 1?No. 4 cylinder ignition coil(s) P2623: High pressure fuel pump

DTC Description	Confirmed DTC	Pending DTC
P0088 Fuel Rail Pressure Too High

Problem verification (idling):

Problem verification (idling)

?1.	Record all the on-board snapshots with the HDS.

?2.	Turn the vehicle to the ON mode.

?3.	Clear the DTC with the HDS.

?4.	Start the engine.

?5.	Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

?6.	Select the DI Fuel Pressure Test in the INSPECTION MENU with the HDS.

?7.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P0088 Fuel Rail Pressure Too High

Is DTC P0088 indicated?


	YES

The failure is duplicated. Go to step 3.


	NO

Go to step 2.

Problem verification (test-drive):

Problem verification (test-drive)

?1.

Test-drive the vehicle for several minutes in the range of these recorded on-board snapshot parameters:

	ENGINE SPEED
	VEHICLE SPEED
	MAP SENSOR
	TP SENSOR
	APP SENSOR
	ECT SENSOR 1
	FUEL PRESSURE CONVERTED FROM PF SENSOR
	FUEL PRESSURE DIRECT INJECTION SYSTEM
	IAT SENSOR (1)

Signal	Current conditions
Signal	Values	Unit
ENGINE SPEED
VEHICLE SPEED
MAP SENSOR
TP SENSOR
APP SENSOR
ECT SENSOR 1
FUEL PRESSURE CONVERTED FROM PF SENSOR
FUEL PRESSURE DIRECT INJECTION SYSTEM
IAT SENSOR (1)

?2.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P0088 Fuel Rail Pressure Too High

Is DTC P0088 indicated?


	YES

The failure is duplicated. Go to step 3.


	NO

Intermittent failure, the system is OK at this time. Check for a poor connection or loose terminals at the fuel rail pressure sensor, the high pressure fuel pump, and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?

Fuel rail pressure sensor check 1:

Fuel rail pressure sensor check 1

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Remove PGM-FI main relay 2.

?3.	Start the engine, and let it idle until it stalls.

?4.	After the engine stalls, press the accelerator pedal to the floor and crank the engine several times.

?5.

Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
FUEL PRESSURE CONVERTED FROM PF SENSOR	Less than 2,000	kPa

Do the current condition(s) match the threshold?


	YES

Go to step 4.


	NO

Replace the fuel rail (fuel rail pressure sensor).?

Fuel rail pressure sensor check 2:

Fuel rail pressure sensor check 2

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Install PGM-FI main relay 2.

?3.	Start the engine.

?4.	Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

?5.	Snap the throttle for several times.

?6.

Check the parameter(s) below with the HDS.

NOTE: Use the Line Grape Setup mode with the HDS to compare the values.

Signal	Current conditions
Signal	Values	Unit
FUEL PRESSURE CONVERTED FROM PF SENSOR
FUEL PRESSURE DIRECT INJECTION SYSTEM
RELIEF VALVE

Are both values almost the same, and does the RELIEF VALVE indicate Normal?


	YES

The fuel rail pressure sensor is OK. Go to step 5.


	NO (the values are not the same)

Replace the fuel rail (fuel rail pressure sensor).?


	NO (Abnormal is indicated)

Replace the high pressure fuel pump.?

Fuel pressure check (low pressure side):

Fuel pressure check (low pressure side)

?1.	Check the fuel pressure.

Is the fuel pressure OK?


	YES

Replace the high pressure fuel pump.?


	NO

Check the fuel supply system (low pressure side).?